Cutting tool for earth, rock, and stone



May 22, 192s.

w. E. sTERK ET Al.

CUTTING TOOL FOR EART'rL-FOCK, AND STONE n lFiled July 6, 1925 Patented May 22, 1928.

' UNITED STATES 1,671,052 PATENT OFFICE.

WILLIAM EpWAED STERN AND ERNEST G. HANSEN, or Los ANGELES, CALIFORNIA; sAID ERNEST G. HANSEN AssIGNoE rro CLAUDE B. DUnsT.

CUTTING TOOL FOR'EARTH, ROCK, AND STONE.

Application led .'fulyv 6,

-An object of this invention is to provide tools for cutting or drilling earth, rock and stone that are highly effective in cutting the material and which when in use are au- 5 tomatically sharpened so that it is never necessary to regrind them. That is we provide tools having cutters that are molded or otherwise embedded n softer metal that is easily worn when brought into worklng -l'contact with earth, rock and stone so that when worn it exposes the cutters that are suiciently hard to cut into the material. In other words cutting edges of the harder metal are gradually and automatically exposed and maintained as the softer metal is worn away. g A

Another object of the invention is to provide a rotary tool formed of relatively soft metal and having spaced teeth in which a thin hardened steel ribbon isembedde'd and arranged-so thatits cutting edges are near er to the facesthan the flanks of the teeth so that a major portion of the reinforcing soft metal is rearward Aof the ribbon, thereby leaving a minor portion Yof the soft metal in advance of the ribbon to be worn away to expose its cutting edges.

Another object of the invention is to provide a tool for deep well drilling that will save considerable time and labor in the respect that'the tool will remain in place on the drillrod and'be continued in act-ion, if

so desired, until it is entirely worn, away, as it is automatically sharpened as previously stated. 'Heretofore lit has been necessary to expand considerable time and labor to frequently and repeatedly remove the drill rods from deep wells to resharpen the bit;'and it is well understood that it. is a long, arduous task vto remove two or three thousand feet of 'drill rod so that the drill bits now in ...scuse can,4 be made accessible for resharpening with additional time and labor expended to replace them; and as stated an object\of this invention is to save time and labor un'- necessarily expended in removing and rei placing drill rods and bits. In the respect of providing a drill bit for use until its cutting-"member .is entirely worn away the invention is broadly new and basic.

Features of the Invention are shownm the construction. and comblnation and ar- :rangement of parts whereby a tool for cutting earth, rock and stone is providedthat 1925. Serial N0. 41,755.

constructed in accordance with this inven- Fig. 2 is a longitudinal section on the line 2-2 of Fim 1 showing a detail construction of the bit and also showing it attached to a deep well drill rod.

Fig. 8 is an enlarged cross sect-ion on lin 3-3 of Fig. 1.

Fig. 4 is -a central longitudinal section through a mold showing a sh tail bit afte it has been cast. I v

Fig. 5 is a grouped side and edge view of a cutter ribbon usedin forming the fish tail bit s hown in Figs. 1, 2, and 3.

Fig. 6 is an enlarged cross section through a twistl drill bit. l l

, The sh tail bit 1 is provided with a bod 2 that preferably is made'of a cheap so t metal that will easily wear away when brought into frictional Contact with earth, rock and stone; 'and this body is provided with a threaded stem dof usual construction so that the bit can be detachably secured to, a drill rod 4 and operated tol drill a hole in a deep well not shown butwell understood in the art.

'Thebody 2 is provided with oppositel arranged integral teeth 5, 6 through whic a cutter ribbon 7 is extended and arranged so that the edges of the ribbon are flush with the edges of the teeth; also the ribbon is'preferably arranged so that its exposed edges 8 are nearer to' the faces 9 than the flanks 10 of the teeth. In other words the ribbon is arranged in the teeth 5, 6 so that there is a heavy reinforcing or a major por tion of soft metal. behind the ribbon to hold it up againstnthe work of cutting the earth, rock and stone and a minor portion of the softmetal in advance of the ribbon to be worn away to expose the cutting edges of' an'd also that the ribbon can wide or nari row, short or llong as best suited to be fitted' into the tool lin which they are to be employed; and also the thickness of the ribbon can be varied relative to'light or heavy work in which they are engaged.

Preferably the ribbons 7 are first arranged in a mold 11 sothat when it is filled with y, 'molten metal to form the body 2y the ribbons? will be molded or otherwise embedded therein. The ribbons 7 are erforated with staggered holes 12 through w ichthe molten metal can low and in which it solidifies to form bondsv thatare adapted to firmly secure the cutter Vribbons vin place and also unite the faces 9 to the flanks l() of the teeth. i The tool may be constructed in lthe ferm 1ozf a twist stone drill as shown in'Fi'g. 6.

In operation the tool is attached to aQdrill rod or similar aplliance and ,rotated or driven into the eart rockand stone'in the usual-way, and frictional engagement of the soft body lof the tool with the material will wear it away so as to expose the cutting edges of the -ribbons that are hard enough to cut the material.

y It is understood. that thel hardened ribbon will be slowly worn away and as it does the body also w1ll be correspondingly worn" to :o exposejust enough of the ribbon to eiicientcut away the material; and the tool can l 'thus be driven until the yribbon isentirely ras to present cutting edges at vopposite sides -of the` cutter, substantially as set forth.

. 2. A tool for cutting earth, rock, and stone,

v including a metal body adapted `to be detach- -ably secured to a drill rod, extensions inte- Y gral with said body, a thinhardened steel ribbon imbedded in said vextez'i'sions-and ar= ranged diagonally so that its cutting edges are nearer to the face than the liianks of said ed be" constantly exposed as the `"tool 'is use.

In witness whereof, we have 'hereunto af fixed our signatures. f

WILLIAM EDWARD STER-K'. f ERNEST G, HANSEN.

`the tool is automatically earth, rock and-stone, 40

extensions, whereby the cutting edges of the l .ribbon will be heavily reinforced and adapt- 

